2014
2014 二叉树（链式存储）
cpp
#include<iostream>
#include<bits/stdc++.h>
using namespace std;
typedef struct Node{
struct Node *left;
struct Node *right;
int high=0;
double weight;
}node;
double sum=0;
void visit(node *t){
int lop=0;
if(t->left != NULL){
t->left->high = t->high+1;
lop = 1;
}
if(t->right != NULL){
t->right->high = t->high+1;
lop = 1;
}
if(lop == 0){
sum += t->weight * t->high;
}
}
void dfs(node *t){
if(t != NULL){
cout << t->weight << endl;
visit(t);
dfs(t->left);
dfs(t->right);
}
}
node* buildnode(int w){
node* tmp = (node *)malloc(sizeof(node));
// tmp->high = 0;
tmp->weight = w;
tmp->left = tmp->right = NULL;
return tmp;
}
void first(node *t){
if(t != NULL){
// visit(t);
cout << t->weight << " " << t->high << endl;
first(t->left);
first(t->right);
}
// also
// if(t == NULL) return;
// // visit(t);
// cout << t->weight << endl;
//
// first(t->left);
//
// first(t->right);
//
}
int main(){
node* n1 = buildnode(1);
node* n2 = buildnode(2);
node* n3 = buildnode(3);
node* n4 = buildnode(4);
node* n5 = buildnode(5);
node* n6 = buildnode(6);
node* n7 = buildnode(7);
n1->left = n2;
n1->right = n3;
n2->left = n4;
n2->right = n5;
n3->right = n6;
n4->right = n7;
dfs(n1);
cout << "sum = " << sum << endl;
first(n1);
return 0;
} 2017
2015 单链表（带头结点）
cpp
#include<iostream>
#include<cstring>
using namespace std;
typedef struct Node{
int data;
struct Node *next;
}node,*list;
const int N = 100010;
int a[N];
void func(Node *head){
node *p;
node *r;
p = head;
while(1){
int x = p->next->data;
if(x < 0) x = -1*x;
if(a[x] == 0){
a[x] = 1;
p = p->next;
}
else{
r = p->next;
p->next = r->next;
free(r);
}
if(p->next == NULL) break;
}
}
node* create(int n){
node* p;
p = (node*)malloc(sizeof(node));
p->data = n;
p->next = NULL;
}
void func2(Node *head){
node *p;
p = head;
while(p->next != NULL){
cout << p->next->data << " ";
p = p->next;
}
return;
}
int main(){
node *head;
node *s1;
node *s2;
node *s3;
node *s4;
head = create(-1);
s1 = create(2);
s2 = create(2);
s3 = create(1);
s4 = create(1);
head->next = s1;
s1->next = s2;
s2->next = s3;
s3->next = s4;
// bianli
func2(head);
func(head);
cout << endl;
func2(head);
return 0;
}
2017
2017 二叉树中序遍历
cpp
#include<iostream>
using namespace std;
typedef struct Node{
char data;
struct Node *left, *right;
}node;
void visit(node *t){
cout << t->data << " ";
}
void bianli(node *t,int h){
if(t != NULL){
// 根 和 叶子
if(h > 0 && t->left!=NULL && t->right!=NULL) cout << "(";
bianli(t->left,h+1);
visit(t);
bianli(t->right,h+1);
if(h > 0 && t->left!=NULL && t->right!=NULL) cout << ")";
}
}
node* create(char data){
node* s;
s = (node *)malloc(sizeof(node));
s->data = data;
s->right = NULL;
s->left = NULL;
return s;
}
int main(){
node *s1 = create('*');
node *s2 = create('+');
node *s3 = create('4');
node *s4 = create('-');
node *s5 = create('3');
node *s6 = create('2');
node *s7 = create('1');
s1->left = s2;
s1->right = s3;
s2->left = s4;
s2->right = s5;
s4->right = s6;
s4->left = s7;
bianli(s1,0);
return 0;
} 2019
2019 链表（快慢指针、反转链表、链表重排）
cpp
#include<iostream>
#include<cstring>
using namespace std;
typedef struct Node{
int data;
Node *next;
}node;
node* create(int data){
node *n = (node *)malloc(sizeof(node));
n->data = data;
n->next = NULL;
return n;
}
void print(node *head){
node* p;
p = head;
while(p->next != NULL){
cout << p->next->data << " ";
p = p->next;
}
cout << endl;
}
void reverse(node *head){
node *p;
p = head->next;
head->next = NULL;
while(p != NULL){
node *t = p->next;
p->next = head->next;
head->next = p;
p = t;
}
}
void change(node *head){
node *q, *p;
// 1. 快慢指針 來确定中间位置
q = head;
p = head;
while(q->next != NULL){
p = p->next;
q = q->next;
if(q->next != NULL) q = q->next;
}
// cout << "## " << q->data << " " << p->data << endl;
// 2. 反转链表
// 头插法 头就是 p
reverse(p);
// cout << "p: " << p->data << endl;
// node *h;
// h = p;
// h->next = NULL;
// p = p->next;
// while(p!=NULL){
// node *t = p->next;
// p->next = head->next;
// h->next = p;
// p = t;
// }
// cout << "T: ";
// print(head);
// 3. 按题目要求进行插入
node *f = head->next;
node *r = p->next;
p->next = NULL;
// r = r->next;
// if(r->next == NULL) cout << "!!!!!!!!!!!!!!!!!!";
// cout << "r: " << r->data << endl;
while(r!=NULL){
node* t2 = r->next;
r->next = f->next;
f->next = r;
f = r->next;
r = t2;
}
}
int main(){
node* head = create(-1);
node* n1 = create(1);
node* n2 = create(2);
node* n3 = create(3);
node* n4 = create(4);
node* n5 = create(5);
head->next = n1;
n1->next = n2;
n2->next = n3;
n3->next = n4;
n4->next = n5;
n5->next = NULL;
// n1->n2->n3->n4->n5
print(head);
// reverse(head);
// print(head);
change(head);
print(head);
return 0;
}
模拟题1
输出二叉树任意节点到根节点的路径（链式存储）
cpp
#include<iostream>
#include<cstring>
using namespace std;
typedef struct Node{
int num;
struct Node *left, *right;
struct Node *front;
}node;
void visit(node *t){
if(t->left != NULL){
t->left->front = t;
}
if(t->right != NULL){
t->right->front = t;
}
}
void first(node* t){
if(t!=NULL){
visit(t);
cout << t->num << endl;
first(t->left);
first(t->right);
}
}
void print(node *t){
cout << "the route is ";
while(1){
cout << t->num << " ";
t = t->front;
if(t == NULL) break;
}
cout << endl;
}
node* create(int num){
node* s;
s = (node *)malloc(sizeof(node));
s->num = num;
s->front = NULL;
s->right = NULL;
s->left = NULL;
return s;
}
int main(){
node *s1 = create(1);
node *s2 = create(2);
node *s3 = create(3);
node *s4 = create(4);
node *s5 = create(5);
node *s6 = create(6);
node *s7 = create(7);
s1->left = s2;
s1->right = s3;
s2->left = s4;
s2->right = s5;
s3->left = s6;
s4->left = s7;
first(s1);
print(s7);
return 0;
}